Informing and Advancing Effective Policy

Preschool is important, but it’s more important for poor children

Stakes were low but passions ran high as fervid 4-year-olds shouted the names of farm animals in Spanish and then in English. “Vaca, cow! Pollo, chicken!” Acing the translation, they snapped colorful tokens onto matching pictures as I watched a feisty round of bilingual bingo at a California preschool last month.

Meanwhile, enthused political leaders are gambling sizably more, suddenly promising free and universal preschool for all families. In his State of the Union address, President Obama renewed his pitch to boost annual pre-kindergarten spending by $7.5 billion. New York Mayor Bill de Blasio is pushing to outbid Gov. Andrew M. Cuomo’s go-slow plan to extend preschool to all young children. Democratic leaders in California unveiled a blueprint to subsidize pre-K for all children, even aiding those from wealthy families.

But an unbounded entitlement would not reduce children’s early gaps in learning. It could even exacerbate disparities. The issue is how, not whether, to invest more in preschool, mindfully preventing learning disparities before they emerge. Poor youngsters enter kindergarten already four to six months behind their middle-class peers in oral language and preliteracy skills. Nor is the issue whether the nation can afford to lift poor children: Americans spend more than $53 billion each year on their pets, far more than family and government outlays for child care and preschool.

But as the pre-K bandwagon gains steam, it’s careering into hazardous territory. Policymakers must take stock of evidence that has emerged over the past decade and get beyond the hyperbolic mythology stirred by well-meaning preschool advocates.

Myth 1:All young children benefit from preschool. The pre-K lobby hopes to extend formal schooling a year or two below kindergarten as an entitlement for all families, no matter how rich or poor. But youngsters from middle-class and well-off homes benefit little from preschool, according to four independent teams of scholars, each tracking large national samples of children over the past decade.

Yet these scholarly groups consistently find distinct and lasting gains for poor children, as I discovered intracking of 14,162 youngsters nationwide with Stanford University economist Susanna Loeb. The minuscule gains experienced by middle-class children largely fade out by fifth grade, according to a second longitudinal study overseen by the National Institute of Child Health and Human Development. Still, gains for poor children persist with greater strength when they attend high-quality preschools and then enter comparatively robust elementary schools.Politicians such as de Blasio ignore these consistent findings when arguing, as he did last year, that subsidized pre-K should be “for everyone, doesn’t matter if you’re wealthy, doesn’t matter if you’re poor, doesn’t matter what color you are.” But empirically, a child’s home environment sharply conditions the efficacy of preschool.

This paper examines the effects of different child care arrangements on children’s cognitive and social proﬁciencies at the start of kindergarten. Using data from the Early Childhood Longitudinal Study, we identify effects using OLS, matching and instrumental variables estimates. Overall, center-based care raises reading and math scores, but has a negative effect for socio-behavioral measures. However, for English-proﬁcient Hispanic children, the academic gains are considerably higher and the socio-behavioral effects are neutral. The duration of center-based care matters: the greatest academic beneﬁt is found for those children who start at ages 2–3 rather than at younger or older ages; negative behavioral effects are greater the younger the start age. These patterns are found across the distributions of family income. The intensity of center-based care also matters: more hours per day lead to greater academic beneﬁts, but increased behavioral consequences. However, these intensity effects depend on family income and race.